Electromechanical movement.



'r' nT nn sTATns PATENT crimen.

GEORGE HOWLETT DAVIS, OF WEST ORANGE, NEW JERSEY.

ELECTROIQCECHANIGAL MOvEMENT. v

No; 895,242.` I

To all who/n it may cof/wem: f e Be it known that I, GEORGE HowLnTT DAVIS, a citizen of the United States, residing at 'est Orange, in the county of' Essex and State of New Jersey, have invented new and useful Improvements in Electromechanical Movements, of which the following is a specification.

My invention relates to electro-mechanical movements, and more particularly to an electro-magnetic actuator designed to produce a uick strong stroke.

One o ject of my invention is to rovide a device of this character which sha operate with a permanently closed magnetic clrcuit, and thereby have a much higlher efficiency than apparatus employing the usual air gap.

A further object of the invention is to rovide .an electro-mechanical movement w lich shall be silent in its operation, and avoid the usual clicking sound incident to the movement of an armature.

.With the above and other objects in view, the invention consists in the construction and arrangement of parts hereinafter described and illust-rated in the accompanying drawinffs, in which:-

iigure 1 is a side elevation showing my invention as applied to an electric piano action. Fig. 2 is a si e elevation on an enlarged scale, of. my improved armature and connected parts, showing thev armature in retracted position. Fig. 3 is a similar view showing the armature attracted. Fig. 4 is a perspective view of the armature.

Referring to the drawings in detail, 1, 1 re )resents a pair of magnet coils surrounding po e-pieces set into a yoke 2, thereb" forming a horse-shoe magnet. The yo (e 2 extends up along the site of the magnet and serves to support a bow shaped leaf spring 3, carrying the armature, in a manner hereinafter described.

The armature is best shown in Fig. 4. It consists of three sections, pivoted together, viz.-a block 4, having winUs 6, and a pair of rockers, 5, pivoted to said wings, as at 7, thus forming an articulated structure.' The rockers 5 are formed with rounded, arcshaped lower surfaces, and are adapted to rest normally on the tops of the pole pieces, as shown in Fig. 2.

The spring 3 is lattened at its end and shaped to it the top of block 4, and the ASpecication of Lettera Patent.

Application filed July 11,' 1907. Serial No. 383,230.

Patented Aug. 4, 1908.

spring and block are provided with suitablev perforations to receive a bolt 8, which is secured in 'said block.

The above described arrangement results i in a floating structure, the several sec tions being secured together, and to the s ring, but having no fixed point of sup ort.

y this-construction the armature is ren ered bodily movable. A

The bolt 8 is provided with a shank -9 which extends down between the magnet coils, and is connected to whatever device it is desired to actuate. this shank as passing downwards through the yoke and secured in a cuit 10, to which is pivoted a shoe 11, adapted, when the magnet is ener ized, to be brought into contact with a.l

A connection 13 elli-Vv..Y

revo ving drum 12. tends from said shoe to the hammer actuating mechanism of a piano. This is a- Well known form of electric piano action. It will be understood, however, that this showing is but illustrative of -one of the numerous uses to which my invention is adapted.

The operation of .my improved armature is as follows :-V.fhen in normal osition, the rockers 5 rest on top of the `o epieces, and

In Fig. 1 I have shown I' the resiliency of the spring 3 olds the block 4 elevated, so that the rockers are in contact with the pole ieces near their outer ends,

only, as at 5"', *ign 2. It will be noted, however, that there is no air` gap, but that the rockers are alw ys in contact with the polepieces, thus forming a completely c osed magnetic circuit. When the magnets are energized, there is a strong tendency for the lines of force, which thread through the rockers 5 and block 4, to shorten. As a result of this tendency, the rockers are caused to roll downward at their pivoted end, so as to contact with the polepieces at a point nearer \their inner ends, as at 5b Fig. 3. The spring 3 is thus flexed and the block 4 lowered, this producing a thrust on the bolt 8, which is connected vwith the device to be actuated. This rolling action of the rockers gives an operation which is smooth and noiseless, and at the same time, sharper and less sluggish than that of a solenoid. Also, owing to the fact that the air gap has been eliminated, there is very little magnetic leakage, and a very eiiicient magnet results.

What I claim is 1. A magnetic circuit comprising fixed and an armature therefor comprising a plurality of floating hinged sections. V

- 4. In combination, an electro-magnet, of the horse-slioe ty e and an articulated armature therefor, bri ging the poles thereof.

5. In combination, an electro-.magnet of the horse-shoe ty e, and an armature comprising articulate sections, some of which are in Contact with the magnet poles.

6. In combination, an electro-"magnet, and an articulated larmature therefor forming therewith a permanently closed magnetic circuit.

7. In combination, an electromagnet, and

` an armaturetherefor comprising a pluralit of pivotally connected parts, some of Whic i are provided with curved faces adapted to roll on the poles ofsaid in cgilet.

8. In combination, an e ectroinagnet and an armature therefor, said armature com- .prising a central block movable to and from said magnet and a pair of rockers pivotedl thereto.

9. In combinatron an electro-magnet, and an armature therefor, said armature comprising a central block, and a pair of rockers ivoted thereto and formed with arc-shaped aces adapted to rock on the poles of said magnet.

10. In combination, an electromagnet, an

armature therefor com risingr a central block and a pair of rockers iinged thereto, and a spring yieldingly supporting said block.

11. 'In combination, an electro-magnet, an armature therefor comprising a pair of pivoted rockers adapted to rock on the poles of said magnet, a yoke for said magnet, and a bow s )ring secured to said yoke and serving to hold said armature in its retracted position.

In testimony whereof I have hereunto set l my hand in presence 'of two subscribing witnesses.

GEORGE HOWLETT DAVIS. Witnesses:

' R. E. SMi'rH,

H. M. ROBERTS. 

